The present invention is to a new and distinct grapevine plant designated ‘Sunpreme’ and botanically known as Vitis vinifera L. This new grapevine is the result of hybridization between A4-162 (seeded mother vine) and C82-88 (seedless pollen parent), both parents being unpatented. The original vine was planted in a field plot in Fresno, Calif. The new variety has been tested as selection B82-43 at Fresno and at Parlier in the San Joaquin Valley of California.
This new and distinct variety of grapevine produces white-skinned seedless berries of the stenospermic type that dehydrate naturally on the vine to produce raisins. The natural raisining of grape berries of the present invention typically occurs during the month of August, allowing for an early harvest as compared with tray-dried raisins of variety ‘Thompson Seedless’ in the San Joaquin Valley of Central California.
The ‘Sunpreme’ grapevine is characterized by producing medium-sized, white-skinned seedless berries that raisin naturally on the vine without cutting of fruit-bearing canes. The berries dehydrate to a state ready for harvest early in the season as compared with the harvest pick-up date of traditional tray-dried ‘Thompson Seedless.’ ‘Sunpreme’ grapevines set a full crop of grape clusters when spur-pruned, as compared with very limited production of ‘Thompson Seedless’ when pruned in a similar manner.
The new variety is distinguished from its seed parent, A4-162, in that the new variety has seedless berries with white skin, whereas A4-162 produces red-skinned berries with viable seed. Clear differences in berry skin color also distinguish the new variety (berry skin color is white) from pollen parent C82-88 (berry skin color is red).
During 2001, dormant cuttings of the new variety were taken from the mother vine in the Fresno vineyard for clonal propagation and advanced testing in Parlier, Calif. Rooted cuttings of the present invention were planted and allowed to establish at the advanced testing site. All propagated vines arising from the original mother plant have been observed to be true-to-type, with both vegetative and fruit characteristics of the original plant being maintained through propagation.